Anonymous communication networks (ACNs) enable Internet browsing in a way that prevents the accessed content from being traced back to the user. This allows a high level of privacy, protecting individuals from being tracked by advertisers or governments, for example. The Tor network, a prominent example of such a network, uses a layered encryption scheme to encapsulate data packets, using Tor nodes to obscure the routing process before the packets enter the public Internet. While Tor is capable of providing substantial privacy, its encryption relies on schemes, such as RSA and Diffie-Hellman for distributing symmetric keys, which are vulnerable to quantum computing attacks and are currently in the process of being phased out. To overcome the threat, we propose a quantum-resistant alternative to RSA and Diffie-Hellman for distributing symmetric keys, namely, quantum key distribution (QKD). Standard QKD networks depend on trusted nodes to relay keys across long distances, however, reliance on trusted nodes in the quantum network does not meet the criteria necessary for establishing a Tor circuit in the ACN. We address this issue by developing a protocol and network architecture that integrates QKD without the need for trusted nodes, thus meeting the requirements of the Tor network and creating a quantum-secure anonymous communication network.

翻译：匿名通信网络（ACNs）能够实现互联网浏览在防止访问内容被追溯至用户的方式下进行，从而提供高度隐私保护，例如防止个人被广告商或政府追踪。以Tor网络为代表的这类网络采用分层加密方案封装数据包，并利用Tor节点在数据包进入公共互联网前模糊化路由过程。尽管Tor能够提供实质性隐私保护，但其加密方案依赖RSA和Diffie-Hellman等算法分发对称密钥——这些算法易受量子计算攻击且正被逐步淘汰。为应对这一威胁，我们提出一种替代RSA和Diffie-Hellman量子抗性方案来分发对称密钥，即量子密钥分发（QKD）。标准QKD网络依赖可信节点跨长距离中继密钥，然而量子网络中可信节点的依赖机制不满足ACN中建立Tor电路的必需条件。我们通过开发无需信任节点的QKD集成协议与网络架构解决该问题，从而满足Tor网络要求，构建出量子安全的匿名通信网络。